Re: [PATCH v2 0/6] Harden userfaultfd

[Stephen Smalley]

On 2/11/20 6:27 PM, Daniel Colascione wrote:
> On Tue, Feb 11, 2020 at 3:13 PM Casey Schaufler <casey@xxxxxxxxxxxxxxxx> wrote:
> > On 2/11/2020 2:55 PM, Daniel Colascione wrote:
> > > Userfaultfd in unprivileged contexts could be potentially very
> > > useful. We'd like to harden userfaultfd to make such unprivileged use
> > > less risky. This patch series allows SELinux to manage userfaultfd
> > > file descriptors and allows administrators to limit userfaultfd to
> > > servicing user-mode faults, increasing the difficulty of using
> > > userfaultfd in exploit chains invoking delaying kernel faults.
> > >
> > > A new anon_inodes interface allows callers to opt into SELinux
> > > management of anonymous file objects. In this mode, anon_inodes
> > > creates new ephemeral inodes for anonymous file objects instead of
> > > reusing a singleton dummy inode. A new LSM hook gives security modules
> > > an opportunity to configure and veto these ephemeral inodes.
> > >
> > > Existing anon_inodes users must opt into the new functionality.
> > >
> > > Daniel Colascione (6):
> > >    Add a new flags-accepting interface for anonymous inodes
> > >    Add a concept of a "secure" anonymous file
> > >    Teach SELinux about a new userfaultfd class
> > >    Wire UFFD up to SELinux
> > >    Let userfaultfd opt out of handling kernel-mode faults
> > >    Add a new sysctl for limiting userfaultfd to user mode faults
> >
> > This must be posted to the linux Security Module list
> > <linux-security-module@xxxxxxxxxxxxxxx>
>
> Added. I thought selinux@ was sufficient.

scripts/get_maintainer.pl can be helpful in identifying relevant lists 
and maintainers for each patch.  I don't use its output blindly as it 
tends to over-approximate but since your patches span the VFS, LSM 
framework, and selinux, you do need to include relevant 
maintainers/lists for each.